(Adds Sampo comment, shares)
HELSINKI, May 20 (Reuters) - Finnish investment and insurance group Sampo has increased its stake in small Finnish bank Aktia to 6 percent, in what it described as a financial investment.
Sampo, which also owns large stakes in Nordea, the biggest bank in the Nordic region, as well as Danish insurer Topdanmark, now holds about 6 percent of Aktia stock and 0.9 percent of its voting rights, it said on Tuesday.
Sampo has no plans to take over the small bank, a company spokeswoman said.
"This is a pure financial investment," she said.
Sampo has been without a retail banking arm since it sold Sampo Bank to Danske Bank in 2006.
Sampo bought 1.5 million Aktia shares in February and on Tuesday added another 2.3 million to its holdings.
Aktia shares were up 2.6 percent to 9.13 euros by 1300 GMT, and Sampo traded 0.9 percent higher at 36.23 euros.
In Tuesday's dealings, Life Annuity Institution Hereditas cut its stake in Aktia to 3 percent of shares and 9.3 percent of votes, while Svenska Litteratursallskapet i Finland lifted its holding to 7.9 percent of stock and 4.6 percent of votes. (Reporting by Jussi Rosendahl; Editing by Pravin Char and Mark Potter)